Sharpening device for lawn mowers



mmh 1s, 1930. B, J; SON 1,751,020

SHAREENING DEVICE FOR LAWN MOWERS Filed July 20, 1928 INVENTOR fzz'sbane I/Zz'son.

ATTORNEY Patented Mar. 18, 1930 UNI/rs n sfrAT-ss BBISBANE1=T- ALISON, 0F DETROIT, MICHGAN snanrnume nnvrcn ronrnwu Mowuas Application filed.V July 20,

rlhis invention relates to improvements in sharpening devices for lawn` mowers, and particularly to light portable devices that may be easily carried from place to place.

5, Among other things the invention aims to provide a Sharpener: with which blades of a lawn mower may be uniformly sharpened throughout their entire length so that no high or low spots are likely to result; with which f.all the blades may be so sharpened that each projects the same distance from the shaft on which they rotate; in which means are provided for varying the angle of the cutting edge of the blades; and into and from which 'l the sharpening means can be quickly insertedand removed.

.Viith these and other objects in view which willbecomeapparent as the specification proceeds, the invention consists in certain novel y construction and combination of parts hereinafter more fully described with the aid of the accompanying drawings, in which:

Figure 1 illustrates a side view of the invention in position on a lawn mower, the latter. beingpartly shown insection.

Figure 2'is a planview of the device, and.

Figures 3 and 4 are. sections on ther lines 34-3 and 4 4 o f Figure 1.

Referring to the drawings, 1 designates the shaft of a conventional lawn mower having a plurality ofA usual concentric spiral blades 2- thereon; 3 indicates the cutting plate in close proximity toone margin of' which each blade in turn passes, and4 is a transverse rod l provided in virtually all makes of lawn mowers.

The device consists of a frame 5 having handlesat its ends. 7 and 8 are upper and lower clamping members. A stud 9 extends upwardly from each lower clamping member 8 through an aperture lO in the frame and through an opening 11 in its upper clamping member 7.' A helical spring-l2 is provided,y around. each stud 9 intermediately of its length which has one end bearingA against each of its members 7 and 8 so that when a nut l'onthe upper end of the stud is loosened the said members are forced apart. On each side ofthe frame 5 between bear-ing. surfaces 7? and. 8"JL of the clamping members 7 and 8 1928. Sela1 N`o. 294,136.

sharpeningmembers 14 are held.y Inthe accompanying drawings, ordinary files arey shown` employed4 for this purpose, but: obvi. ously any sharpening members4 having iilelikev cutting surfaces may be utilized since the file tangs are not` used.

' 15, 161and 17 designate three elongatedfver, ticalzslots through the frame 5. Throughthe slot 15 a threaded pin 18 extends which hasa downturnedtVsblock 19 0n its lower end. 20 60. and 2OEL designate nuts in threadedengage-- ment with the `pin above and'below the frame.l 5, so that the distance of the Vlblock` below` the frame may beset as desired. Through the central slot 16a sleeve Al-:extends which.` 652 has a flange 2l.-a that; bears againstthe undersideiof the frame 5.and a nut 22 mits-upper end by which-it is heldlin position. yEhroug-h. the sleeve 21' a spindle 28 is rotatably ar rangedz on the lower. end; of which latter, is. a '705. disc 24 having a horizontal slit 24a infitsunderside. rlhroughvthe upper end'of the. spin.- dleQ?) a. pin 23a' isv provided-to,preventftheL said spindle fromV fallingthrough the-sleeve,

though. other means for accomplishingE this purpose' may be utilized; Throughthe thirdi slotl 11'?? athreadedarni 25xextends'. Nuts 262 .y I and 26a, one above and one below thezfra'me 5,.infthreaded engagement withlthe armpermit vertical adjustment off the latter; Onl the 30o lower end ofi the arm a guidesuch astheball 271 is' provided. l

The longitudinali and vertical adjustment ofi the Vlblock` 119 with respect to thexframe 5 allow it to be so seti that it may engage theA brace rod? 4 ofalmostV any make or type ofA lawn mower, and-the block being- Vishaped'; permits iti being used on various' sizes of' rods.` The. longitudinali andf .vertical adjustment'ofl thethreadedi arm 25 Ypermits the Yball guide 27 being soisetl thatl the'lat'terwill* rest on the cutting. plate 3 of almost any machine. The adjustment permitted by the threadedarm 25k may also be employedftoregulate the angularity of the sharpening members 14 ,mi relative to the blade 2 being sharpened; The longitudinali` adjustment provided for vthe sleeve.y 21' and its spindleQB permit the disc being so positionedrelativeto the Veblock 1 9 andiball: guide 271' that the slit '24%.will engage ien the margin of the blade-to be sharpened.` By moving the sleeve 21 longitudinally in its slot 16 the cutting angle at which the bladeis sharpened may also be varied, as the position of the disc 24 is then moved' relative to i' tent that its radius isreduced materially below that of the otherblades. Again owing to the width of bearing surface of the two sharpening members 14 the danger of high andlow spots developing inthe blades as they are sharpened is reduced to a minimum, Whilein the foregoing the preferred embodimentot1 the invention has been described and shown, it is understood thatthe construc- Y tion vis subject to such modifications and alterations as fall within the scope of they appended claimsj 'i WhatI claim as my invention desire to secure by Letters "Patent is:

Y 1. vIn agd'evice of the character'described,

the combination of a `'frame'having sharpening means attached to its underside adapted to VbeVlr moved Vtransversely of and to bear against a lawn mower blade, a block depend- ,ingk fro'mcsaidframe adapted to be moved with the latter along V`thetransverse rod of f the lawn Vmower, and `means depending from j said frame and rotatable about a substantially Avertical `axis adapted to hold that portion of theblade Vagainst which the sharpeningmeans is then bearing in they desired position under` 'thelatten i y;

Y of the character described, thercombination'of a frame having-sharpeningmeansattachedto its underside adapted f 2.- In a; device to be moved transversely of` and to bear against alawn mower blade, a block depending fromA said frametowards one of its extremities adaptedv to ber moved vwith said frame along ythe transverse rod of the lawn mower, meansdependin from said frame] androt'atable about. a su stantially vertical axis adapted to holdthat portion-ofA the blade against which the sharpening means kare then bearing in the` desired position under-the latter, and means mounted on said frame adjacent its end remote from said block for varying the angle at which that portion of the blade is held against which the sharpening means bear. g

3. kIn a'device of the character described, thecombination of a frame having sharpening means attached to its underside'ada ted to be moved transversely of and to ear againstra lawn mower blade, a block depending from said frame adapted to be moved with the latter along the transverse rod of the lawn mower, means depending from said frame and rotatable on the latter adapted to hold that portion of the blade against which the sharpeningmeans are then bearing in the desired position under the latter, and means permitting variation of the distance between the block landthe rotatable means for holding the blade in position.

4. Ina deviceiot the character described, the combination of a'frame,sharpening means held thereunder adapted to be moved transversely of and to bear-against a-lawn mower blade, 'a v-V-block` depending Vfrom, saidV frame adapted to be moved with :the latterftrans- Aversely along the transverse rod of the 'lawn Y mower,'said V-bloclrbeing adjustable at rightr 1 angles Vto said frame, a lspindle' extending soY through said frame'fand held yagainst axial g movement, said spindleY having a slit in itsV underside adapted to engage the blade to be sharpened and hold that portion ofthe latter ,Y against whichthe sharpening meansv are bearing in the .desired position, and means per- -llttngvariation of the distance between the 7 il-block and the spind1e Y a A v5.111 a devicey of thecharacter` described,l the combination of a trama-sharpening meinbersheld underV said trame adapted to be".

moved transversely of and .to bear against a able bothV longitudinally and at right anglesf to said frame, a sleeve extending through said frame adjustable longitudinally of the latter, 'Y and a spindle extending, through said sleeve j held agains'tea'xial movement, vsaid* spindleY Y,

having a'slitin its underside adaptedV to engage the blade and hold'ithat portion lof the latter against which the sharpeningfmenibers are bearing inthe desired position. Y '6'.- In a deviceof the rcharacter described, the combination of a frame, sharpening memlawn mower blade, a V-block depending trom bers held under said Jframe adapted to be n moved "transversely of vand to bear against avlawnvmowerxblade, a V-'blocl depending from said frame adapted Vto be moved with the latter along the'transverse rod ofthe lawn mower, Y, a sleeve extending through f 'saidif frame, a spindle through said sleeve and rotatable therein having aslit in its underside."

adapted to engage the blade being sharpened f and hold that portion of thelat-ter against which the sharpening means are bearing in the desired position, and an adjustable guide adapted tofbear on .therey cutting plate of the.

lawn mower'.

7. In a device ofthe character described. i. the combination of a trame, a block dependi ing therefrom adaptedto be moved longitudinally on a transverse'rod of aI lawn mower.

clamping members extending laterally from said frame on both sides thereof, sharpening members supported by said clamping members one on each side of said frame and sub# stantially parallel therewith, and a guide projecting under said frame between said sharpening members having a slot in its underside adapted to engage the margin of a lawn mower blade and to turn the latter relative to said sharpening members as the frame is moved longitudinally of the blade.

8. In a device of the character described, the combination of a frame, a block depending therefrom adapted to be moved longitudinally on a lawn mower tie rod, clamping members integral with said frame extending laterally on both sides thereof, sharpening members supported by said clamping members, one on each side of said frame and substantially parallel therewith, upper clamping plates on said sharpening members, means for holding said upper clamping plates in position, and a guide rotatable in said frame between said sharpening members having a slot in its underside to engage the margin of a lawn mower blade and turn it into sharpen-k ing position relative to said sharpening members, said sharpening members operating with their length substantially at right angles to the length of the blade surfaces being sharpened.

BRISBANE ALISON. 

